1~10000之间的所有对称数

　　数组反转

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const findPalindromeByReserveArray = () => {     const arr = []     for(let i = 1; i <= 10000; i++){         const str = String(i)         const strArr = str.split('')         if(str === strArr.reverse().join('')){             arr.push(i)         }     }     return arr }

　　字符串前后index值比较

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const findPalindromeByCompareIndex = () => {     const arr = []     for(let i = 1; i <= 10000; i++){         const s = String(i)         const length = s.length         let startIndex = 0         let endIndex = length - 1         let flag = true         while(startIndex < endIndex){             if(s[startIndex] === s[endIndex]){                 startIndex++                 endIndex--             }else{                 flag = false                 break             }         }         if(flag) arr.push(i)     }     return arr }

　　翻转数字方法

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const reverseNumbers = (num) => {     let rev = 0     while(num > 0){         rev = rev * 10 + num % 10         num = Math.floor(num / 10)     }     return rev }

　　使用翻转数字

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const findPalindrome = (n = 10000) => {     const reserveNumber = (num) => {         let base = 0         while (num > 0) {             base = base * 10 + num % 10             num = Math.floor(num / 10)         }         return base     }     const res = []     while (n > 0) {         if (reserveNumber(n) === n) res.push(n)         n--     }     return res }

 

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const isReserveNum = (num = 1234321) => {   const s = String(num);   for (let i = 0; i < s.length; i++) {     const v = s[i];     if (v !== s[s.length - 1 - i]) return false;   }   return true; };